NOTE Some symptoms of heat stress are similar to symptoms of nerve agent poisoning. The rapid action of nerve agents calls for immediate administration  of  the  antidotes  atropine  and pralidoxime chloride (2-PAM C1). Atropine acts to dry up secretions in the respiratory tract and to stimulate the central  respiratory  functions,  and  2-PAM  C1 simultaneously relieves muscle paralysis, especially in the respiratory tract. Both antidotes are self-injected into the lateral thigh muscle by the use of automatic injectors. Blister Agents Blister agents act on the eyes, mucous membranes, lungs, and skin. Blister agents include mustard vapors and mustard liquids. Mustards burn and blister the skin they contact, damage the respiratory tract when inhaled, and cause vomiting and diarrhea when absorbed. The d eg r e e  o f  d a m a g e  d e p e n d s  o n  t h e  t y p e  a n d concentration of the agent, the weather, the amount of activity of the individual, and amount of exposure time. Blister agents are effective even in small quantities and produce both immediate and delayed injuries. Mustard vapors burn any area of the skin; but, the burn is most severe in moist areas, such as the neck, genitals, groin, armpits, bends of knees, and elbows. Redness of the skin follows in 1/2 to 36 hours after exposure.  This  condition  may  be  accompanied  by intense itching, and blisters may then appear. Stiffness, throbbing pain, and swelling may also occur. A few hours after breathing the mustard vapor, a victim experiences irritation of the throat, hoarseness, and coughing. After severe exposure, the lining of the respiratory system swells and interferes with breathing. Frequently, pneumonia develops. If the whole body is exposed to mustard vapor, the body  goes  into  a  state  of  shock.  This  reaction  is accompanied by nausea and vomiting. Personnel who suspect contamination of their eyes or face must seek overhead shelter and flush the eyes with  potable  (drinkable)  water  from  a  canteen  or shower.  Mild  exposure  to  skin  can  be  treated  by applying calamine lotion or topical steroid creams. All blisters should be opened, drained, and cleansed with tap or saline water. Any exposure to mustards require medical care by a corpsman or medical personnel. Blood Agents Blood  agents  inhibit  the  action  of  an  enzyme responsible for transferring oxygen from the blood to the cells of the body. Thus the cells become starved for oxygen. Inhalation is the usual route of entry for blood agents. The symptoms produced by blood agents depend on the concentration of the agent and the duration (length of time) of the exposure. Typically, either death occurs rapidly or recovery takes place within a few minutes after removal of the victim from the toxic atmosphere. High  concentrations  of  blood  agent  cause  labored breathing within a few seconds, violent convulsions, followed  by  cessation  (stoppage)  of  breathing completely. Finally, the heart stops only a few minutes after initial exposure. The symptoms of exposure to blood agents are shown in the following chart: 13-4 Student Notes: INITIAL SYMPTOMS ADVANCED SYMPTOMS Increased respiration Headache Giddiness Dizziness Increased pulse rate Red, flushed skin Convulsions Coma Death